One of the first steps you take when you are making a decision about your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Le Mars you can determine when to plant helianthemum by reviewing the USDA zone info.

Planting Calendar for Helianthemum

Frost tolerance for helianthemum:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Since helianthemum are one of those plants that can tolerate a little bit of cold weather you can plant them just a bit earlier in the year than more sensitive plants.

The earliest that you can plant helianthemum in Le Mars is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant helianthemum and expect a good harvest is probably September. Any later than that and your helianthemum may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your helianthemum indoors.

Last Frost Date

In Le Mars the average date of last frost happens on April 15. You should expect an average low temperature of -20°F in the coldest months of winter.

Just be sure to remember that USDA zone info for Le Mars is not always accurate and the actual date of last frost will vary from year to year. Half of the time in Le Mars you get a frost after April 15 so just be sure to be ready to cover your helianthemum in the event of a late frost.

USDA Zone Info for Le Mars

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Le Mars

You may be interested in your other planting guides for Le Mars.